Self-locking lifting device



J. McDOWELL.

SELF LOCKING LIFTING DEVICE;

APPLICATION FILED JUNE 25. 1920.

1 73,438. Patented Apr. 5, 1921.

INVENTOR Jikn/jl' flvwell,

ATTORN EYS JOHN MCDOWELL, OF NEWARK, NEVI J SELF-LOCKING- LIFTING DEVICE.

intense,

Specification of Letters Patent.

Patented Apr. 5, 31921;

Application filed June 25, 1920. Serial No. 391,801.

T 0 all w ham it may concern Be it known that I, JOHN MCDOWELL, a citizen of the United States, residing at Newark, in the county ofEsseX and State of New Jersey,have invented certain new and useful Improvements in Self-Locking Lifting Devices; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to characters of reference marked thereon, which form a part of this specification. t

The present invention relates, generally, to improvements in self-locking lifting devices for handling building stone and similar materials; and the invention has reference, more particularly, to a novel selflocking means for engaging blocks of stone, and the like, for the purpose of hoisting or lifting the same.

The invention has forits principal object to provide a very simple, cheap, safe and efficient self-locking gripping device adapted to be engaged with stone blocks and the like for lifting or hoisting the same; said device comprising a mechanism so devised and arranged that the weight of the stone, when engaged therewith and lifted thereby. serves to produce a self-locking grip of the device upon the'stone, so that all danger of the latter falling or being loosened or accidentally uncoupled from the hoisting means is eliminated, and consequently a very easily applied and safe gripping device is provided. v

' Other objects of the present invention, not at this time more particularly enumerated,

- will be clearly understood from the follow scribed, and then finally embodied in the claims appended hereto.

The invention is clearly illustrated in the accompanying drawings, in which Figure l is a side elevation of the novel self-locking lifting device operatively engaged with a block of stone, or the like, in lifting relation thereto.

Fig. 2 is a front end or edge elevation of the same.

Fig. 3 is a vertical longitudinal section through the same, said view being drawn on an enlarged scale, a J

Similar characters of reference are employed in all of the hereinabove described views, to indicate corresponding parts.

Referring now to said drawings, the reference-character 1 indicates the complete novel self-locking lifting device made according to and embodying the principles of my present invention, the same compris, ing an anchor member 2 provided at one end with anintegral right angled extension or gripping bit 3. Said anchor member 2is provided, at the end thereof opposite said gripping bit 3 with an enlarged portion or butt 4 provided with a transverse opening '3. The reference character 6 indicates a gripping lever member, which is provided, intermediate its ends, with a through slot or socket 7 into which projects said butt 4iof said anchor member 2. The side walls bounding said slot or socket '7 of said lever member 6 are provided with transverse openings swhich, when said butt 4: of said anchor member 2 is inserted within said slot or socket 7, are alined with said opening 5 of said butt, whereupon a transverse pivot pin 9 may be inserted through said alined openings 8 and 5, and suitably secured against accidental displacement, thereby pivotally mounting said gripping lever 6 on the butt 4C or". said anchor member 2. The upper end of said lever member 6 is provided with an opening 10 forming an eye-portion adapted to receive a clevis link and bolt 11,

or any other suitable form of means for attaching to the upper end of said lever member the lifting rope or cable 12 of a hoisting tackle or other lifting means. The

lower free end of said lever member 6 is r chamfered, as at 13, to provide a gripping jaw.

In the drawings the reference-character 14 indicates a block of stone, or the like. Usually in handling cut building stones and similar material, the stones are provided with holes drilled or bored thereinto to provide seats for pins upon which the hoisting slings or tackle may be operatively s cured. In the use of my novel self-locking lifting device it is only necessary to provide the block 14 with a single hole 15. This hole 15 is bored at an angle of approximately forty-five degrees to the plane of the stone surface into which said hole enters, and is preferably slightly removed or oft-set from the center of the block.

In connecting my novel self-locking lift ing device with a block of stone thus pre pared, the gripping bit 3 of the anchor member 2 is inserted in said angular opening 15. Since the gripping bit is at a right angled relation to said anchor member 2, and since the opening 15 is inclined to approximately forty-live degrees, it follows, that said anchor member 2 will project upwardly from the surface of the block at an angle of approximately forty-five degrees, and will be positioned to extendtoward the nearer end I; of the stone or block. The anchor member 2 being thus arranged in fixed relation to the block 14:, the lower end of the lever member (3, as pivoted to the butt l of said anchor member, will incline downwardly with its gripping jaw 18 in engagement with the surface of the block at a point intermediate the hole 15 and the nearer end X of said block, while the upper end of said lever member 6 will inc-line upwardly and inwardly. When the lifting device is thus arranged in operative relation to the block 14, and an upward pull is imparted to the hoist rope or cable 12, the pulling strain of the latter applied againstthe weight of the block, will pivot said lever member 6 0n the pivot pin 9, and will tend to swing the gripping jaw 13 tightly and firmly down upon the surface of the block, thereby tent ing to force the block toward the gripping bit 3, and efficiently preventing the stone from moving endwise and downwardly off of said gripping bit 3. Since the location of the opening 15 of the block 14: is slightly offcenter, it follows that the weight of the farther end Y of the block will somewhat overbalance the nearer end X, and consequently the tendency of said nearer end X will be to lift against the gripping jaw 13,

so that in addition to the pulling strain tending to swing the lever member so that the gripping aw 13 bears downwardlyupon the surface of the block, the overbalanced weight of the fart-her end Y of the block will cause an upward bearing movement. of the surface of the block against said gripping jaw 13, all of which tends to a great security of gripping effect by the lifting device upon the block, and also operating to render the lifting device self-locking the moment the lifting pull is applied therethrough to the block.

vFrom the above description it will be apparent that I have provided a very efficient, yet exceedingly simple construction of lifting device for the purposes in View, and at the same time a lifting device which is assuredly safe, so that danger of accidental disengagement of the block therefrom during the lifting operation is eliminated.

I am aware that some changes may be made in thearrangements and combinations of the several devices and parts, as well as in the details of the construction of the same, without departing from the scope of my present invention as set forth in the foregoing specification and as defined in the appended claims. Hence, I do not limit my invention to the exact arrangements and combinations of the various parts as de scribed in said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the accompanying drawings.

j I claim p 1. A self-locking lifting device for the purposes described, comprising an anchor member having a lateral extension at one end for engagement in an angularly disposed opening provided in the side of the material to be lifted, and a gripping lever member pivoted intermediate its ends to the opposite end of said anchor member, the upper free end of said lever member being adapted to be connected with a hoisting means, while the lower 'end of the same engages the upper surface of the material to be lifted.

y 2. A self-locking lifting device for the purposes described, comprising an anchor member having at one end an integral right angularly projecting gripping bit, a gripping lever member, said gripping lever member having a receiving socket intermediateits ends for the reception of the opposite end of said anchor member, a pivoting means passing transversely through said receiving socket and in engagement with said opposite end of said anchor member disposed in said socket, the upper end of said gripping lever having an eye-portion to receive the attachment of a hoisting means, and the lower end of said gripping lever having a chamfered gripping jaw.

3. A self-locking lifting device for the purposes described, comprising an anchor member having at one end an integral right angularly projecting gripping bit, a perforate butt portion at the opposite end of said anchor member, a gripping lever member having a receiving socket intermediate its ends into which said butt portion of said anchor member is fitted, a transverse pivot pin extending through the sides of said lever member and through said perforate butt portion of said anchor member, and the upper end of said gripping lever member having an eye-portion to receive the attachment of a hoisting means.

In testimony that I claim the invention set forth above 1 have hereunto set my hand 10 this 22nd day of June 1920.

JOHN MCDOWELL.

Witnesses:

GEORGE D. RICHARDS, ETTA C. GROSOH. 

